Field of the Invention
The present invention relates to an image processing apparatus, image processing method, and storage medium, and particularly to a technique of reading out and processing additional information from a print product in which information other than image information, for example, voice information, text information, and pieces of information about an image are embedded as additional information in the image.
Description of the Related Art
There has been proposed a technique of embedding information in a print product so that the information does not stand out (to be referred to as “invisible” hereinafter). This technique is called a digital watermark or steganography and has been developed rapidly in recent years.
Japanese Patent Laid-Open No. 2003-348327 discloses a method of embedding multiplexed information other than visible image information in a print product, and a method of extracting multiplexed additional information in the print product from information input by using a scanner (image scanner).
However, the following problem arises in Japanese Patent Laid-Open No. 2003-348327.
It is very difficult to perform shooting accurately a plurality of times while holding a camera-equipped mobile phone or smartphone by the hand and shifting the shooting position. To easily perform shooting by the user, it is desirable to execute a setting (continuous shooting mode) of automatically releasing the shutter in every predetermined time while moving the camera by the hand, or execute a moving image shooting mode. In this case, however, a captured image may blur under the influence of the relative speeds of movement of the hand-held camera and a stationary print product, failing in extracting embedded additional information.